Bruton's tyrosine kinase (BTK) is a member of the Tec family of non-receptor tyrosine kinases, and is an important signaling enzyme which is expressed in all hematopoietic cell types except for T lymphocytes and natural killer cells. BTK is an important control factor associated with survival, differentiation, proliferation and activation of B-cells, and takes an important role in signaling of B-cells (Non-Patent Documents 1 and 2). A B-cell receptor (BCR) of the cell surface signals into cells through BTK existing in the downstream of BCR and, therefore, it is considered that abnormal activation of the signaling pathway of B-cells accelerates proliferation and survival of cancer cells of B-cell lymphoma, chronic lymphocytic leukemia and the like (Non-Patent Document 3). It is known that BTK also plays an important role in the signal pathway of a large number of other cells, and it is said that BTK is involved in allergic diseases, self-immune diseases, inflammatory diseases and the like (Non-Patent Document 1). For example, it is known that BTK plays an important role for signaling of a high affinity IgE receptor (FcεRI) in mast cells, and degranulation decreases and the production of proinflammatory cytokines decreases in BTK-deficient mast cells (Non-Patent Document 4). It is suggested that BTK is involved in systemic lupus erythematosus (SLE) in a test of a BTK-deficient mouse (Non-Patent Document 5). Furthermore, the BTK mutant mouse exhibits resistance to the onset of collagen-induced arthritis (Non-Patent Document 6). Therefore, the compound having a BTK inhibitory activity is useful for the treatment of diseases which are involved in BTK signaling, for example, cancer, B-cell lymphoma, and chronic lymphocytic leukemia, and is also useful for the treatment of allergic diseases, self-immune diseases and inflammatory diseases.
The compounds which having a BTK inhibitory effect mentioned above have been reported. (Patent Document 1)